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Kathryn 'Kat' McDonough reviews statements she made during 8th day on the stand at Strafford Superior Court in Dover. McDonough is the key witness for the prosecution in the trial of Seth Mazzaglia, accused of killing University of New Hampshire student Elizabeth 'Lizzi' Marriott in his Dover apartment on Oct. 9, 2012. (Pool Photo by John Huff/Foster's Daily Democrat)

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DOVER -- In final statements of his more than five-day cross-examination of Kathryn “Kat” McDonough, defense attorney Joachim Barth called her understanding of reality “dubious and doubtful” Thursday morning and said she has consistently failed to recognize the devastating impacts of the October 2012 death of UNH student Elizabeth “Lizzi” Marriott.

“You have no appreciation for Ms. Marriott’s life,” Barth said. “Ms. McDonough, I don’t have any further questions for you.”

McDonough, 20, responded to Barth’s statements in a choked-up voice, asking how he could make such a claim.

“You don’t know me. You don’t know what I’ve been through,” she said. “You have your ideas, but I have spent so much time trying to understand this. I have spent all this time not being able to say anything to anyone.”

McDonough said prior to the ongoing trial, she’d long been unable to tell the truth about what happened to Marriott on Oct. 9, 2012, in the Dover apartment she shared with accused murderer Seth Mazzaglia, 31.

“I’ve been locked in my thoughts – of course I think about her,” McDonough continued Thursday. “This is just the beginning, where I can actually explain what really happened to her."

Earlier Thursday, Barth said to McDonough, “It seems at almost every juncture you have been a victim in this process in your efforts to tell the truth.”

Mazzaglia is facing first- and second-degree murder charges in the death of Marriott, a 19-year-old from Westborough, Mass. McDonough testified last week that she was sitting next to Marriott on the night of her death when Mazzaglia began strangling Marriott from behind with a rope, and that Mazzaglia then raped Marriott’s limp body.

Barth has accused McDonough of killing Marriott during a night of rough sex that could have caused suffocation and a seizure.

“We have talked about your repeated lies,” Barth said to McDonough on Thursday. “Your capacity to lie and lie repeatedly and consistently, you admit.”

McDonough again acknowledged, as she has since her testimony began June 3, that she initially lied to investigators, Barth’s legal team, Mazzaglia and others. She said she told those lies and created a story about rough sexual contact that led to the “accident” of Marriott’s death in attempts to protect Mazzaglia.

“I was willing to lie for him,” McDonough said Thursday. “I was willing to do just about anything to save him.”

McDonough is serving a 1½- to three-year prison term after pleading guilty last July to charges including witness tampering and hindering the investigation, as part of a plea agreement. She has testified that she helped cover up the murder and rape of Marriott, whose body has never been found.

Barth returned Thursday morning to recorded interviews and statements McDonough made in Barth’s law office on Oct. 15 and 17, 2012, just days after Marriott’s death and Mazzaglia’s arrest Oct. 13.

McDonough, who later spoke to a grand jury in February 2013 and reached a plea deal with prosecutors in July 2013, said she was lying throughout much of the October interviews with Barth’s legal team.

The different stories created a back-and-forth in Barth’s questioning Thursday.

“You described to us that the kind of harness you put on Liz Marriott would make it hard to breathe if you pushed your head forward, correct?” Barth asked.

“We didn’t actually put a harness on her, so it was just something I came up with,” McDonough said.

“You described the encounter with Liz Marriott to us on the 15th and confirmed it again on the 17th?” he asked.

“I described a fictional encounter,” she replied.

“Part of that encounter included you sitting on Ms. Marriott’s face for 10 to 15 minutes,” Barth said.

“That was part of the fictional encounter,” McDonough replied.

“You described, literally, the feelings you had during this act of sexual domination,” Barth pressed.

“That was the way I described something that didn’t actually happen,” McDonough said.

Barth then recounted how McDonough told his legal team that Marriott had “what appeared to you to be a seizure” and “that you freaked out” and that “you characterized this as an accident.”

“To you, yes,” McDonough said. “I told you that it was an accident.”

Mazzaglia’s defense took more than an hour Wednesday afternoon in court to play a video of McDonough in Barth’s law office on Oct. 17, 2012. She had come to the office to review and revise a summary statement she had given legal staff Oct. 15.

McDonough appeared at ease in the video, smiling and laughing several times while talking with an investigator.

She said in the video that Marriott kissed both her and Mazzaglia that night. McDonough also used hand gestures to describe how she touched Marriott while Marriott was on top of her. At one point in the video, McDonough stood up to demonstrate how she straddled Marriott.

Barth asked her Thursday about her demeanor in the video.

“I can’t deny the fact that I do tend to laugh when I’m nervous,” McDonough said. “That was a way for me to calm down.

“By laughing, I was able to release some of that nervousness, to stay calm,” she added a few minutes later.

“Does that make you a really good liar then, or a better liar now?” Barth asked.

“I’m not lying now,” McDonough said. “I’ve been told that I suck at lying. I don’t know if people actually believed my story or not.”

Barth also referred to a conversation between McDonough and Rochester resident Roberta Gerkin, a friend of Mazzaglia’s who has testified in his ongoing trial and who came to the Dover apartment on the night of Marriott’s death. Gerkin and her boyfriend, Paul Hickok, saw Marriott’s body lying on the floor that night.

The conversation to which Barth referred Thursday took place in the months after Marriott’s death. McDonough didn’t know that Gerkin was recording the conversation, Barth said.

Barth said McDonough described Marriott’s death to Gerkin as “a stupid, stupid, stupid thing” and as a “pothole” in McDonough’s life.

“It was a bump in the road in my life, but a really, really big one,” McDonough said Thursday.

McDonough has maintained in her testimony that she repeatedly lied to Gerkin in conversations following Marriott’s death.

“When she seemed so adamant about wanting answers, I decided to give her a story that I had already given someone else,” McDonough said Thursday.

Barth again referred Thursday to McDonough’s seemingly relaxed demeanor in the October 2012 interviews, and asked whether McDonough’s more guarded, more hesitant answers in court over the past week have represented her “truth-telling” demeanor.

“I’m telling the truth as it is,” McDonough said. “I’m trying to fix as much broken things as I can fix.”

Assistant Attorney General Peter Hinckley, who guided McDonough through more than two days of direct testimony that began June 3, began his re-direct questioning late Thursday morning.